Which Version Miui Is Better For Mi2s? V5 Or V6

Can anyone tell me wat is the best MIUI version for the Xiaomi MI2S?
V5 or "V6 with new merged partitions".
And wich rom date?
For now I am using V5 from 4.12.5.
Are there also some where available screenshots to see from the latest V6 version with lollipop?
There are some things that are very usefull in V6. Count bubble etc.